Quantitative evaluation of data is the foundation of scientific research. The Biostatistics Core provides resources to assist in the planning, conduct and analysis of the proposed research in such a way that quantitative analyses are appropriate and illuminating. The Core also assists in the dissemination of appropriate information both within and external to the SPORE and the Siteman Cancer Center (SCC). This core represents an extension of the strong Biostatistics Core within the Siteman Cancer Center, and funding is only requested for the SPORE-specific support required. This efficient model takes advantage of the core infrastructure in place. The Core is staffed by a dedicated biostatistician for each of the 4 projects. In addition a designated faculty member is devoted to collaborations concerning specialized bioinformatics issues. The Core staff are collaborators with the Project Co-leaders. The staff of the Core will meet weekly among themselves and regulariy with Project leaders to review the progress in each Project and the SPORE overall and to discuss methodological issues. The Biostatistics Core will serve as a resource and collaborator for the four main projects proposed in this application. Career Development Program and Developmental Research Program projects and the SPORE Cores. Specifically the Biostatistics Core will: 1. Continue to participate in the design of all projects (including developmental and career development) and will advocate for the application of appropriate statistical and methodological techniques. 2. Continue to merge information from the SPORE research with information about samples that have been entered into caTISSUE which is supported by the SPORE Tissue and Pathology Core to produce analytic datasets which are deidentified and easily distributed to investigators. 3. Collaborate in data analysis and report preparation for all Cores and Projects. 4. Collaborate in the design of all forms to be used. 5. Support data entry and data management procedures to achieve cost-effective data acquisition. 6. Facilitate access to data collected by the projects and cores. RELEVANCE (See instructions): This shared resource will acquire and store tissue samples (blood and bone marrow) from patients with leukemia. These samples will be invaluable to investigators as they test new hypotheses and therapies.